cold as a mackerel vs cold enough to freeze the balls off a brass monkey

cold as a mackerel

adj
  • Very cold (in temperature, emotionally, etc.). 

  • Completely unconscious. 

cold enough to freeze the balls off a brass monkey

adj
  • Extremely cold. 

How often have the words cold as a mackerel and cold enough to freeze the balls off a brass monkey occurred in a corpus of books? (source: Google Ngram Viewer )